Abstract: A convolutional interleaver for interleaving a data stream composed of N number of data with predetermined interleaving level B to randomize the data stream for an error correction, comprising: an input buffer; a memory; an address generating unit; an output buffer; and a controller, and a method for generating an address of the memory are disclosed. In the method for generating an address of the memory, a basic memory of which the number of vertical end is B-1 and horizontal length is (B-1).times.M cell is transformed to an intermediate memory of which the number of vertical end is B-1 and horizontal length is (B/2).times.M cell, and a physical address for accessing the intermediate memory is generated.

Abstract: A communication system is provided that includes a mechanism for selectively addressing memory banks depending upon the configuration of that system. The communication system can therefore operate in accordance with two possible modes of operation. According to a first mode, the local CPU can access one set of memory banks concurrent with an external device accessing the other set of memory banks. According to a second mode of operation, either the local CPU can access the memory banks or an external device can access the memory banks, one exclusive of the other. In one version of the second mode of operation, address signals to the memory banks can be physically connected leaving signals free to be used as general purpose input/output signals. The mechanism by which memory banks can be addressed and data transferred to and from those banks readily lends itself to communication applications to which the present system may be attributed.